I mean its not far from real conditions. Best accuracy for finding their Vf in circuit would be to use their real K170 destined to power them in the build of course. To produce such a buffer in the way some meticulous members put it together in this thread, forget it cost wise indeed.

Problem is their self dissipation. Would need some special TO-92 double sink to help them and lock their drift by coupling their temp in pairs. Buffer's Zo is limited by the necessary output series resistor anyway, but the more conductance the less THD of course. Also the more Ciss unfortunately, maybe 10K pot max if like that with K170V in the audio part. Not good in the PSU part due to capacitance and drift.

Speaker manufacturers have been selecting measured components for decades.

Every driver gets measured. Every critical crossover component gets measured. The computer then "cherry picks" the combination of drivers and components to get the final speaker within that model's tolerance range.

This could easily be applied to a simple amplifier.
But is there a market for tens of thousands that the computer could send out?